Expanding the EDA500

You can put whatever HDD in your available slots, it all depends on what is goal and what you want to do with it!

So what are your issues?

How can I help you?

I am an aspirant, not a guru, but because a guru hasn’t responded, here’s my two cents.

Assumption 1:  By “smaller drives” you mean smaller storage capacity in TBs, not smaller physical size as in 2.5” vs 3.5”.

Assumption 2:  The EDA500 was loaded with the 5 TB drives from a Factory Default state, and no smaller capacity drives have ever been installed in the EDA500 since the last Factory Default. 

If so, the current volume will not expanded after installation of smaller capacity drives. The volume will only expand after installation of drives equal to or greater than 5 TB.

If smaller capacity drives have been installed since the last Factory Default, then you may be able to expand the volume by adding drives equal to or greater than the previously installed drive capacity.

Download the NAS logs and look at the mdstat.log file. If the primary RAID (md127) is the only one in the md1XX series (e.g., md126, etc, ignoring md0 and md1) and if /dev/md/data-0 further down shows a raid1 Array Size of approximately 5 TB (<5000 GB), then the current volume will not expand with any drive capacity less than 5 TB without a Factory Default reset.

For more information, see the following available at https://community.netgear.com/t5/Using-your-ReadyNAS/XRAID-turned-RAID5-into-RAID6-when-adding-a-drive/m-p/1120084#M113353:

- For Horizontal Expansion, on ReadyNAS OS6, in X-RAID mode, starting in RAID5 or 6, the added disk needs to be at least as big as the smallest HDD ever in the array since the time it's in RAID5 or 6 (so 3 HDDs or more), starting in RAID1, the added disk needs to be at least as big as the smallest HDD in the array since the time it's in RAID1 (so 2 HDDs).

This is because in RAID1, the primary RAID (md127) is extended in case of Vertical Expansion, so the new member needs to be at least as big as the members of the primary (and only) RAID array.

In RAID5 or 6, the primary RAID (md127) is not extended in case of Vertical Expansion. Instead, secondary RAID(s) are created. So the new member needs to be big enough to host the same size partition as all the sdX3's (members of the primary RAID array).

For basic information about Horizontal Expansion: http://kb.netgear.com/app/answers/detail/a_id/23134

I posted a more thorough reply that now seems to be gone. Won't do that again. In sum, a smaller capacity drive won't expand a RAID volume in which only larger capacity ones have been installed since the last Factory Default—e.g., can't add 3TB drive to expand a RAID volume made up of 5TB drives. See https://community.netgear.com/t5/Using-your-ReadyNAS/XRAID-turned-RAID5-into-RAID6-when-adding-a-drive/m-p/1120084#M113353